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Unusual Mod/con Install

Ironman
Ironman Member Posts: 6,554
I was called to this job a few weeks ago for no heat on a Saturday afternoon. The Buderus G234X had been installed about 10 years prior and had developed multiple problems. Several others had been there trying to fix an intermittent problem of the boiler failing to fire, all to no avail. As soon as they left, the problem would re-occur. Their usual solution was to "clean the pilot".
When I arrived, I found that the 2107 Logamatic control was bad, the vent damper was sticking, the pilot head had been mangled and the boiler was severely corroded due to being connected to a 150 year old unlined chimney. The low water temp maintained by the 2107's reset curve further exacerbated the corrosion. The fact that it was twice the size that my load calc called for did not help matters either.
I advised the HO that it was not worth the investment of lining the chimney and replacing the 2107 on a boiler that had suffered so much corrosion. Keep in mind that Buderus makes the most corrosion resistant cast iron so it took a lot of abuse to do this to this boiler.
Our solution was to leave the existing boiler in place for a backup and install a new mod/con and indirect. The existing water heater was 30 years old and connected to the same chimney.
We replaced the bad vent damper and pilot, disconnected the 2107 and connected the old boiler directly to a standard thermostat that would be left set a couple of degrees lower than the room control for the new boiler.
The GreenStar is piped to inject into the return of the old boiler. This was the easiest piping arrangement and it keeps the old boiler warm should it ever have to fire. The GreenStar is connected to Bosch's new room control which uses indoor reset and really works nice.
The rating tag is is from the boiler previous to the G234X. The GreenStar is a 35kw and should carry the house down to design temp.
Bob Boan
You can choose to do what you want, but you cannot choose the consequences.
SWEI4Johnpipe

Comments

  • NYplumber
    NYplumber Member Posts: 503
    @EricAune just put a blog post together on his site Mechanical-hub about getting roi and enough with the diamond plate. I have to echo his blog post by saying I agree. With that said, this is what I call bang for the buck. The customer will reap the rewards of this install. To top it off, he has a backup. Good work.
    :NYplumber:
    Rich_49
  • Ironman
    Ironman Member Posts: 6,554
    edited December 2015
    I can't post the price, but I can tell you that I charged him about $2500 less than I normally would have if I had to do all the ancillary things. This was an old gravity system tha had been converted, but I didn't have to drain and fill it because of the location where we Tee'd the new boiler in.

    My 18 year old son, Jeremy, did most of the work (piping, flue, pulling cable).
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    SWEI
  • Ironman
    Ironman Member Posts: 6,554
    NYplumber said:

    @EricAune just put a blog post together on his site Mechanical-hub about getting roi and enough with the diamond plate. I have to echo his blog post by saying I agree. With that said, this is what I call bang for the buck. The customer will reap the rewards of this install. To top it off, he has a backup. Good work.

    Thanks.
    I have to agree about the diamond plate. Occasionally, we'll get the high dollar job in a mansion where we want it to be a piece of art, but that's the exception, not the norm.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.